Cert common name validation (#992)

* x509 Certificates: CommonName length requirements changed to 0

* remove unnecessary validations + update proto gen

* remove debug message to avoid noise in logs

Author: sean-breen

api/grpc/mpi/v1/files.pb.go

@@ -272,10 +272,10 @@ message X509Name {
     repeated string postal_code = 7 [(buf.validate.field).repeated.items.string.min_len = 1];
 
     // Serial Number (SN): Unique identifier or serial number.
-    string serial_number = 8 [(buf.validate.field).string.min_len = 0];
+    string serial_number = 8;
 
     // Common Name (CN): Typically the person’s or entity's full name.
-    string common_name = 9 [(buf.validate.field).string.min_len = 1];
+    string common_name = 9;
 
     // Parsed attributes including any non-standard attributes, as specified in RFC 2253.
     // These attributes are parsed but not marshaled by this package.